Tunable broadband terahertz absorber based on graphene metamaterials and VO2

A tunable broadband terahertz (THz) absorber is designed in this paper, which is composed of graphene, silica medium and phase change material Vanadium dioxide (VO2). By simultaneously changing the fermi level of graphene and conductivity of VO2, the dual-controlled absorber can be realized. The results show that the full width at half maximum of the absorption spectrum is 1.03 THz, the bandwidth with the absorptance above 90% is 0.65 THz, and the absorptance is close to 100% at 1.2 THz. Moreover, the absorptance, transmittance and reflectance of the absorber can be dynamically adjusted from 0 to 99%, 0–65%, and 0–74%, respectively. The large tunability allows the proposed absorber to be used as THz tunable filters, sensors, switches and modulators.